Полиморфизм CYP2D6 и приверженность лечению антидепрессантами

Early discontinuation of antidepressant drugs (ADPs) therapy is common, occurring in about 30% of patients by week 6.1, 2 Among the most relevant reasons for ADP discontinuation are adverse drug reactions and lack of improvement,3 which can be explained by interindividual variability in drug metabolism. Thus, discontinuation of amitriptyline or fluoxetine, two of the most commonly used ADPs worldwide, which are mainly metabolized by CYP2D6, could be related to CYP2D6 genetic polymorphism.

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Despite the limitations of the present study (naturalistic observation, non-fixed dose, lack of evaluation of drug plasma concentrations and efficacy), a relationship between CYP2D6 polymorphism and early discontinuation of fluoxetine or amitriptyline monotherapy treatment was observed. There were differences across CYP2D6 groups in the rate of ADP discontinuation at week 4 (P < 0.01;Table 1). Overall, the rates of ADP discontinuation were 25, 36 and 46% at weeks 4, 8 and 12, respectively; no patient returned after dropout. All UMs discontinued treatment within the first 4 weeks, whereas no PM did so within 12 weeks.

 CYP2D6 ultrarapid metabolism and early dropout from fluoxetine or amitriptyline monotherapy treatment in major depressive patients

STAR*D

The Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial was a longitudinal, multi-center, 5-year study of common strategies for treating depression. To date, it is the United States’ largest National Institute of Mental Health funded study including over 4,000 patients. This four level trial compared traditional augmentation strategies with switching agents (Slide 2).30-34 Unlike most depression studies, in STAR*D the outcome measure was full remission.
In Level 1, the initial monotherapy phase, citalopram (mean dose of 41.8 mg) was effective at achieving remission for only ~30% of subjects. This finding has been accepted as an accurate reflection of clinical experience with any initial monotherapy. The remaining 70% were randomized to either receive bupropion or buspirone augmentation, or switched to one of three antidepressants as monotherapy—bupropion, venlafaxine, or sertraline. Augmentation resulted in a 30% response, while switching antidepressants resulted in ~20% of patients achieving remission. Level 3 included those non-remitters from Level 2 who were then randomized to either T3 or lithium augmentation, resulting in remission rates of 25% and 16% respectively. A Level 3 switch to nortriptyline (NTP) or mirtazapine (MTZ) was in general less successful than Level 3 augmentation, with 20% of NTP patients and 12% of MTZ patients remitting. Level 4 treatment options (monoamine oxidase inhibitors [MAOIs] or venlafaxine–mirtazapine-combination therapy) were provided to patients who had not responded satisfactorily to previous levels of the treatment protocol, and very few experienced full remission (14% and 7% respectively).12,35


An overall analysis of STAR*D results indicates that the chances of achieving and maintaining remission in patients with difficult-to-treat depression diminishes with every additional strategy needed. Those who fully remit early in the course of treatment have a better chance of remaining well than those who experience only symptomatic improvement. STAR*D does not tell us which treatment works better as a first or second adjunct, simply that the greatest chance of recovery appears to lie with the first two sequential treatments.

The Role of L-methylfolate in Depressive Disorders